The Calamity Cannon is the last weapon in the game, excluding the Battering Ram. It packs a powerful punch to anybody or anything that gets in its way. Another advantage is that it deals splash damage similarly to the Galleon Mortar. However, its unique disadvantage is that it can also deal collateral damage to yourself and allies, making it a difficult weapon to master.
The Calamity Cannon is a ranged weapon with a very high range. It doesn't have any recoil when firing nor a Power Shot and is upgraded with Something Wrong. It deals large AoE damage and requires a charge-up time of roughly 1s unupgraded. Much like the Galleon Mortar, it only fires while the Kid stands still, adding to its mobility disadvantages. However its splash adds another disadvantage in that you can also blow yourself up, making it a very dangerous weapon to both yourself and the
Due to the recharge time of the weapon as well as the splash damage, this weapon is NOT suited for close/medium range combat as most enemies can get up close and deal several hits. (Not to mention the collateral you'll take.) This is the number one rule when using the Calamity Cannon. The cruel of you may wish to inflict Massive Irony upon the Ura by 'finishing what they started' (i.e. killing them with the Calamity Cannon), but this is also not advised. Due to the Ura's quickstep abilities, similar effects will result with the use of the Calamity Cannon.
The Calamity Cannon's main use is to turn you into a walking tower by giving you massive damage and multiple-kill functionality while forcing you to remain still. The slow recharge also compounds this effect, meaning that faster-firing weapons such as the Fire Bellows, the Cael Hammer and especially the Duelling Pistols are best-suited for giving yourself a little space before you unleash Nature. Not surprisingly, space is the main focus of any CC (Calamity Cannon) user. You can use its powerful damage to clear out enemies and make space, as well as its knockback. However, it requires good prediction of where an enemy will move, due to the lack of auto-aim for the weapon. (This doesn't really apply in the tablet edition, due to the default autoaim.) Thankfully, the default skill that comes with this weapon, Mancer Missile, essentially rains down destruction on anyone near the Kid, causing powerful damage that compounds with the frag effects.
Any CC user requires a weapon that fires significantly faster and preferably has close-range prowess as well.
Calamity Cannon + War Machete
The War Machete swings in a wide arc and has an incredibly fast attack speed, making it ideal for putting an end to weak melee enemies (Stinkeyes, Squirts), while the Calamity Cannon (preferably upgraded to max with homing) can quickly defeat larger ranged enemies (Scumbags, Massive Windbags) with ease. Combined they can put an end to almost every enemy in the game.
Calamity Cannon + Dueling Pistols